Various substituted 3-aryl-pyrazole type compounds are known in the literature. Such compounds have various utilities, e.g., as chemical intermediates, pharmaceuticals and herbicides.
Among the substituted 3-aryl-5-(halo) alkyl-pyrazoles in the art are those having a variety of substituent radicals on the aryl and/or pyrazole moieties of the compound, e.g., alkyl, carboxyl, alkoxycarbonyl, formyl, phenyl and phenyl substituted with various groups such as alkyl, halo or nitro groups, etc. For example, compounds of this type are known wherein the aryl moiety is a substituted or unsubstituted phenyl radical, in which the substituent radicals are alkyl, cycloalkyl, alkaryl, halogen, trifluoromethyl, etc., and the pyrazolyl radical is substituted in various positions on the nitrogen or carbon atoms with alkyl, halogen, alkoxy, hetero-cycles, S(O).sub.n R members, wherein n is 0-2 and R may be a variety of radicals such as those substituted on the aryl or pyrazole moieties.
Compounds of the above type having utility as herbicides, typically require application rates as high as five or ten or more kilograms per hectare to achieve adequate weed control. For example, Japanese patent application No. 1-225724 by Miura et al. discloses a number of 3-phenyl pyrazole derivatives most of which required a dose of 5 kg/hectare for adequate weed control in both pre-emergent and post emergent tests. In particular, 3-phenyl pyrazole derivatives having alkyl or haloalkyl substitutions in the 4 position of the pyrazole ring were disclosed and exemplified by two compounds having 4-methyl substitutions and in the 5 position either --SCH.sub.3 (compound 360) or --SOCH.sub.3 (compound 570). Only one of these, compound No. 360, was tested for weed control and a dose of 5 kg/hectare was required for effective post-emergent weed control. At 0.8 Kg/hectare, weed control was ineffective.
Thus, in accordance with the present invention, it has been discovered that a novel class of 4-substituted alkyl and haloalkyl arylpyrazole-type compounds have uniquely and surprisingly high phytotoxic unit activity against a spectrum of weeds, including narrow-leaf and broadleaf weeds yet maintain a high degree of safety in a plurality of crops, especially small grains and/or row crops such as wheat, barley, corn, soybeans, peanuts, etc.
The 1-(halo)alkyl-3-(substituted)aryl-4-(halo)alkyl-5-haloalkylpyrazoles described herein are new.